This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Instrument maintenance performed on the 1. Perseptive STR reflectron MALDI time-of-flight mass spectrometer 2. Thermo-Finnigan LTQ electrospray ionization ion trap mass spectrometer fitted with on-line HPLC, and ETD fragmentation facility. 3. Thermo-Finnigan LTQ ion trap mass spectrometer fitted with a vacuum MALDI ion source. *4. Finnigan LCQ-DECA-XP electrospray ionization ion trap mass spectrometer fitted with an in-house constructed MALDI ion source incorporating our CD sample inlet system. 5. Finnigan LCQ-DECA electrospray ionization ion trap mass spectrometer fitted with an on-line microflow HPLC separation unit. 6. Waters Synapt Ion mobility Quadrupole Time-of-Flight Mass Spectrometer *7. Prototype novel high-capacity ion trap-quadrupole tandem mass spectrometer fitted to a prototype Sciex QQTOF mass spectrometer fitted with an in-house constructed MALDI ion source incorporating our automated CD sample inlet system. 8. Perkin Elmer ProTOF orthogonal Injection Mass Spectrometer 9. Finnigan ETD-LTQ-Orbitrap Mass Spectrometer 10. Pharmacia-Amersham Smart HPLC system 11. LC Packings HPLC system 12. Micro-Tech Scientific XtremeSimple HPLC system. 13 Two Agilent HPLC systems Service in the mass spectrometers included maintenance of vacuum pumps, cleaning of the ion source, replacement of ion detectors, repair of electronics;the HPLC systems required maintenance of piston and syringe pumps and replacement of seals, check valves, and trouble shooting.